


Nanika Gives Illumi a Heart

by fearofevrything



Category: Hunter X Hunter
Genre: Gen, I Wrote This Instead of Sleeping, Minor Character Death, This sounds really depressing, but i promise it ends on a very happy and sweet note, but then it devolved into giving illumi an emotional breakdown, i can't believe i was this mean to killua, i'm sorry if anyone is ooc i'm just dumb, illumi has emotions?, like i mean very minor, mentions of silva and kikyo, there is some strong language but not a lot, this started as crack
Language: English
Status: Completed
Published: 2020-06-10
Updated: 2020-06-10
Packaged: 2021-03-03 23:40:05
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,390
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24644206
Author URL: https://archiveofourown.org/users/fearofevrything/pseuds/fearofevrything
Summary: When Killua's lifeless body is dumped on the Zoldycks' doorstep, Illumi breaks. But what starts as gut-wrenching heartbreak leads to a breakthrough no one thought Illumi to be capable of.Or, how Illumi learns to accept his sister and how to be a semi-functional human being in two days or less.
Relationships: Alluka Zoldyck & Killua Zoldyck, Gon Freecs & Killua Zoldyck, Illumi Zoldyck & Killua Zoldyck
Comments: 10
Kudos: 99





	Nanika Gives Illumi a Heart

**Author's Note:**

> This is the first thing I have written that's non-school related in several months, and the longest thing by far in well over a year. I've been suffering from massive writer's block and burnout from school, to the point where even looking at a blank document would make me freeze up. So basically, this was written between the hours of 12-8am and my writing skills are rusty so please go easy on me.
> 
> A huge shoutout to my friend Akaya for helping me come up with this and reading through it many, MANY times throughout the night and offering excellent critiques! I don't think I would have been able to even write this without her answer to my dumb "what would it take to make Illumi break" question.
> 
> Update 7/5/20: Thank you all for reading and for all the kudos and lovely comments! I updated my Twitter handle so if you tried to follow me before and it didn't work, that's why! I like the new one much better lmao. So follow me @hiisokaphobic on twitter!!

Illumi stared down at the lifeless body of his brother in front of him. Whatever cruel bastard that had done it had managed to drop the body on the Zoldyck family’s doorstep, and had, as far as anyone could tell, disappeared without a trace. No, this couldn’t be real. This was just some elaborate scheme Killua had come up with, some sort of cruel joke, right? After all, it did appear as if the white-haired boy could just be sleeping. Illumi nudged Killua’s lifeless body with his foot. When Killua failed to respond, Illumi bent down to pick him up, gracefully placing his arms under the boy’s knees and behind his head.

“Come on Kil…wake up. This isn’t funny.” Illumi gently shook his brother’s body as he walked up the steps into the huge house. “This has to just be one of your stupid jokes right? Come on, wake up.” When Killua still didn’t move, Illumi decided to try the one thing he knew would get him to comply. He continued to walk a little bit further into the house and placed Killua down on a table. Carefully and with practiced grace, a shiny gold needle entered Killua’s forehead. With this, Illumi expected his brother’s eyes to open immediately. When they didn’t, reality hit, all at once, and in the worst way possible.

The room began to spin, and it felt as if the floor had been pulled out from underneath Illumi’s feet. This was real. It was all real. The unimaginable had happened and there was nothing Illumi could have done to stop it. All of a sudden, Illumi found his knees buckling underneath him as he clung to the edge of the table as if he would fall off the face of the earth if he were to let go. He didn’t even notice when Silva and Kikyo made their way into the room, he didn’t hear his mother’s gasp, or his father’s voice. He heard nothing. He could barely see as his father lifted Killua’s lifeless body from the table and carried him off somewhere. He wanted to cry. He wanted to scream, to beg his father to put Killua back, to tell him that surely he would wake up soon. But no sound came out of his mouth, and he just sat there, gripping the table until his nails left deep grooves in the polished wood, gasping for air that just wouldn’t seem to fill his lungs. His mother’s touch on his shoulder brought Illumi back down to earth for a moment. The world was still hazy, and he couldn’t hear her words. He didn’t even acknowledge her presence, instead simply shoving her away and storming off into his room.

In the silence of his room, Illumi let his emotions consume him. He sat on the floor, desperately trying to reason with himself. This was all new to him. Emotions were not something the Zoldycks were encouraged to have. Emotions were likely what got Killua killed. Despite all that, right now he wanted to sob, he wanted to scream and cry and just break down but the tears would not come. So he sat there on the cold floor of his bedroom, heaving and gasping for air. After what felt like hours, he was finally able to get a grip on reality. However, instead of the intense pain he had felt moments before, his chest filled with an indescribable rage. His aura flared around him, leaking bloodlust the likes of which no one in the family had ever seen. His rage was palpable, the air in the entire house became thicker and filled each room with a lingering sense of dread. Suddenly there was a loud crash, as Illumi blindly launched the nearest object at his wall with his entire strength, not even bothering to look at what he was holding, leaving a large hole in the wall and completely destroying whatever it was he had just thrown. Upon hearing the commotion, a butler knocked on Illumi’s door hesitantly, seemingly all but unphased by the bloodlust emanating from the room. The door swung open violently and the butler was greeted by Illumi’s dark, empty eyes, his hair seemingly floating around him and casting a threatening shadow across his face. Illumi didn’t so much as speak before launching several needles into the butler’s vital pressure points, pinning him to the wall before slitting his throat with sharp, claw-like nails. It felt good. It felt real. More real than any of the events that had led up to this moment. Feeling the blood dripping down his hand, seeing the man’s lifeless body, this was the most normal thing about the entire situation. He wanted more. He wanted the blood of the person who killed his brother, and he would not hesitate to kill anyone who stood in his way. The only question now was where to start tracking down his brother’s killer.

  
The first person that came to Illumi’s mind was that little green gremlin who had essentially stolen Killua from him in the first place. He had to be involved somehow. Ever since meeting Gon, Killua had gone soft; he’d begun to think he was capable of being something more than a cold-hearted assassin, of being someone capable of making friends. So he did everything in his power to hunt the kid down and pry information out of him before ending him once and for all. Fuck Hisoka, Illumi had a personal bone to pick with Gon now, and he wouldn’t stop until the kid was dead at his feet. It wasn’t like him to be vengeful, especially not over a personal matter. In fact, had it been anyone else in his family, he likely would have next to no reaction. But Killua was special. Killua had always been Illumi’s favorite and everyone knew it. When he had left home, Illumi was upset, sure. But now? Now he was out for blood.

He tracked Gon to a patch of woods not too far from a small city outside of Heaven’s Arena. It was just past noon, so under normal circumstances, Illumi would have to take extra care to conceal himself, both his physical presence and his aura. But he didn’t care. He wanted Gon to be afraid. He wanted anyone who might stand in his way to tremble in fear.

“You know who killed my brother,” Illumi had his hand at Gon’s throat, hair once again billowing around him and bloodlust pouring from him intensely. The physical pressure exerted from his aura alone would be enough to kill a weaker person, “and you are going to tell me exactly who it was, and how it happened”

The boy’s eyes were wide with a mix of fear and shock. If Hisoka was around to see it, he would be absolutely thrilled to see the powerful aura surrounding him as he fruitlessly struggled in Illumi’s grasp. “What are you talking about?! I talked to him a few days ago, he’s still traveling with Alluka.”

Alluka.

Why hadn’t Illumi thought of that before? That…thing could be the key to bringing Killua back. He knew it had been done before, when Killua used Alluka’s power to save Gon. So why couldn’t the same be true in this case?

“Well, it appears that you were not aware. Killua is dead. And now I am going to find that monster and you are going to force it to bring him back.” Once again, there was no hint of sadness in Illumi’s words. The complete despair he had felt seeing his brother’s lifeless body turned into the rage that now spilled out of him like poison. The violence radiating from him was enough to send any birds and small animals in the area running. “And the more you protest, the slower and more painful your death will be.”

Gon immediately stopped struggling and stared at Illumi with wide eyes and an open mouth. Then his expression immediately changed to one of pure anger. “Killua is dead and you wanted to use me to get your revenge? And now you want me to use Alluka’s power to make you feel better?” Gon’s words were sharp, very surprising for someone with a widely feared assassin’s hand at their throat.

“Yes. That is exactly what I just said. What part of that did you not understand?” Illumi was getting annoyed. Not only did the brat continue to struggle, but he was being incredibly stupid about it. The violence radiating from his presence, his voice, everything about him, had reached a new extreme. Never before had he been this enraged, this bloodthirsty. Killing was generally meaningless to him, it was just a job that had to be done. But now he had a purpose. This was the most passion he had ever felt in his life. This rage should scare him, but it didn’t.

“If you really loved Killua you wouldn’t be making someone else make the wish for you! That’s exactly why Killua kept Alluka away from you in the first place! You just want to use her selfishly. You don’t care about anyone at all, do you?” Bold words. Gon continued to look Illumi straight in the eye as he spoke, continuing to thrash about in an attempt to break free.

He was right though. He was right and Illumi hated it. All at once the realization came crashing down on him, and once more, the world stopped spinning and it felt as if all the air left his lungs. He suddenly released his grasp on Gon’s throat and stared ahead, struggling to maintain his grasp on the world around him. He knew what he had to do. He was going to have to make the sacrifice to save his brother. He had no other choice. If he didn’t do it, if he pushed the wish off on someone else, that person could end up having to kill a lot more people, even another family member. nd if that person failed...it could end up killing not only Illumi, but everyone else. And he couldn’t take the blame for that. He had to try. And he had to ensure that he wouldn’t fail. He had to make the sacrifice.

Fuck.

  
Finding Alluka hadn’t been a challenge. Gon was stupid enough to tell Illumi where Killua was the last time they had spoken, and sure enough, Alluka was still in the exact same place. It was a remote town with only a few major shops and businesses, and one run down motel. That must be where they had been staying. He was able to pay off the bored looking receptionist to tell him the younger Zoldycks’ room number easily enough. The motel was run down and shabby, a place that would have been far below any self-respecting Zoldyck. No wonder the receptionist couldn’t be bothered to put up a fight.

He approached the room and forced his way through the door. He made no effort to conceal his aura. Alluka would be afraid regardless. And he didn’t care who else was affected by his bloodlust. In fact, if anyone were to get in his way, that would be a grave mistake on their part. Illumi thought allowing his rage to be felt was a warning for anyone who might think to stop him. At first glance, the room appeared to be empty, until he saw the unmistakable blue eyes peeking out from the other side of the bed.

“I-Illumi?” A small, quiet voice sounded from Alluka’s hiding place. “You’re going to take me back to the basement, aren’t you?” The fear in Alluka’s voice was enough to prove to Illumi that she was in fact, not a Zoldyck at all. A proper Zoldyck would never be so weak as to show their fear this way. His anger spiked once more at the thought.

“Yes. Killua never should have taken you out of there. You are too dangerous.” Illumi’s voice was cold again. He held no compassion for his sister, he didn’t even acknowledge her existence apart from Nanika. And why should he start now? She was simply a tool for him to use to bring Killua back. “And do not speak to me. I am not your brother. You do not belong in this family.”

Alluka cast her gaze downwards in silent resignation. There was no way for her to fight, there was nowhere to run. Illumi knew this. He knew she would have no choice but to come with him. “Can I at least say goodbye to him?” Her voice was small, and not very hopeful. He hadn’t planned on that, but it could work in his favor. It would allow him to bring Alluka close enough to force Nanika to use her power.

“I suppose I can arrange that. Now come. We are going home.” Without a shred of kindness or a second thought, he grabbed her roughly by the wrist and pulled her off the floor with enough force to cause her to let out a small yelp of pain. “Be quiet,” he hissed, glaring daggers at the girl before dragging her off to take her home.

The journey back to the Zoldyck estate was silent. Illumi had nothing to say to Alluka, and she was too afraid of him to speak, with the rage and bloodlust still pouring out of him only serving to heighten her fear. When they arrived home, Illumi did not say a word to a single butler or family member. He was dead silent and his eyes were empty and emotionless. If not for his threatening aura, he could have been mistaken for a walking corpse. He led Alluka to the room where Killua’s body was being kept, waiting for a proper burial the following day. The sight of his brother’s lifeless body threatened to bring forth the same emotions he had felt the day before. However, this time, he did not allow the grief to surface. He was here for a reason. He had a plan. Killua would be okay. He would be okay. He had to be okay. He had to be. If this didn’t work…if this didn’t work, then Illumi didn’t know what he would do. He didn’t even want to think about it. No, he couldn’t think about it. This had to work.

“Bring Nanika out.” Illumi’s words were not gentle.

“But—” Alluka’s words were cut off.

“Bring. Nanika. Out.” This time, his words were demanding, with an unspoken threat behind them. He was leaving her no choice. She closed her eyes, and opened them to show the telltale empty black voids where her eyes and mouth once were. “Bring him back.” Illumi stared Nanika in the eyes, his own gaze commanding and unwavering.”

“‘Kay”

And with that, a powerful aura was released, and suddenly, Killua’s once lifeless body began to regain color as he started breathing once more. For the moment, he appeared to be asleep. Illumi quietly carried his sleeping brother to his room and placed him gently on his bed. Only after hearing Killua mumble a sleepy and unintelligible sentence did he finally slip out of the room. He exited the room and went back to face Nanika’s inevitable demands.

He was prepared to do just about anything Nanika would ask him to do. But he was not expecting the words that came out of her mouth.

“Brother, pat my head,” she spoke not with the cheerful tone she took with Killua, but a more somber and…almost caring one. No, he must be hearing wrong. This creature wasn’t capable of emotion, right?

“What?” He was confused. No, this wasn’t right. A wish of this caliber should require extraordinary demands. He was prepared to do almost anything, even killing his own family. But this? This couldn’t be right.

“Brother, pat my head” Nanika repeated the same demand again, her tone unchanged. Hesitantly, Illumi reached out to do as she had demanded. Surely the next demand would be what he was expecting?

Nanika smiled, closer to the demeanor she took with Killua. “Brother, bring me my bunny” Again with this? There must be some sort of catch. This isn’t how Nanika’s power worked. The next demand was sure to kill him, right? Again, with the same hesitation as before, he complied. He made the trek down to Alluka’s basement room with Nanika in tow, to retrieve her favorite stuffed rabbit. He handed it to her cautiously as she smiled once more.

Illumi braced himself for the inevitable. This was it. This next demand would kill him. And he was okay with that. He had resigned himself to his fate, sacrificing his own life for the brother he loved dearly. He was ready. He closed his eyes and braced himself for Nanika’s next words.

“Brother….give me a hug.”

Illumi’s eyes shot open and he stared at Nanika in disbelief. Why was she doing this? “Why? Why aren’t you asking me to do something more? My wish was…it should have killed me.” There was silence. And then Nanika spoke again.

“I….love Killua. Brother, give me a hug. I love…Killua.” She spoke more earnestly than Illumi would have ever believed this creature to be capable of. This monster that had only ever brought death and destruction…loved Killua. She loved Killua. She…--

Realization hit Illumi like a wave crashing down on the shore. Without realizing it, he had knelt down and wrapped his arms around his sister, holding her tight.

“Brother…I love Killua…” She repeated this once again, and Illumi could no longer hold back. Suddenly this…this thing seemed more human than even his own parents. Killua had treated her kindly. And she loved him.

“I….I love Killua too.” Illumi’s voice threatened to break. His face suddenly felt wet. Were these tears? No, he was a Zoldyck. Zoldycks did not cry. But he reached one hand up to touch his face, and sure enough, the unmistakable feeling of wetness lingered on his face and hand. She had known. She had known how much he was hurting. She had known how much he loved Killua. And because of this, she had spared his life, all she asked in return for this astronomical wish was a bit of affection. Fuck. No. This couldn’t be right. This couldn’t be happening. But it was. He had to face the truth. Nanika was not a creature made solely for destruction. She was capable of feeling. She was capable of love. Maybe even more than Illumi himself was. And yet, he and his family only saw her as a tool of death and destruction. How could they have been so cruel to her, to Alluka. She was…maybe she was his sister after all. How could they all have been so wrong? He wanted to pull away, but instead he just held her tighter. There, kneeling on the floor of the room Alluka had been locked away in for years on end, Illumi Zoldyck broke down. He began to cry harder as he held on to his sister’s tiny frame. All while she simply…watched.

Illumi was pulled out of his thoughts by Nanika nestling her face into his neck, wrapping her own small arms over his shoulders as if to comfort him. “Thank you…Nanika. I…” He inhaled deeply, barely aware of what he was saying, although he knew his words to be absolute truth, “I am sorry. I am truly sorry for the way we have treated you and Alluka. We all love Killua.” He wiped away the tears that just would not stop coming.

Nanika lifted her head to look at Illumi with a smile. The same smile she only gave to Killua. “’Kay.” She stayed silent for a moment, not looking away. “Brother….I am sleepy…” She once again lowered her head into Illumi’s neck, breathing out a deep sigh before falling asleep in his arms.

He looked down at the small sleeping figure. How could he have been so cruel? Without thinking, he began to gently stroke her hair. “Thank you, Alluka. Thank you.” For now, revenge could wait. All he wanted right now was to enjoy this newfound feeling, and to finally, truly meet his sister.

**Author's Note:**

> Thank you so much for reading! If you enjoyed it, or if you have critiques or advice for my writing please feel free to leave a comment!
> 
> Also feel free to follow me on Twitter or drop me a DM @hiisokaphobic 
> 
> Update 7/5/20: Thank you all for reading and for all the kudos and lovely comments! I updated my Twitter handle so if you tried to follow me before and it didn't work, that's why! I like the new one much better lmao.


End file.
